In general, electronic components containing a ceramic material, such as capacitors, inductors, piezoelectric elements, varistors, thermistors, or the like, include a ceramic body formed of a ceramic material, internal electrodes formed in the ceramic body, and external electrodes mounted on external surfaces of the ceramic body to be connected to the internal electrodes.
Among ceramic electronic components, a multilayer ceramic capacitor includes a plurality of stacked dielectric layers, internal electrodes disposed to face each other with respective dielectric layers interposed therebetween, and external electrodes electrically connected to the internal electrodes.
Multilayer ceramic capacitors have been widely used as components in mobile communications devices such as computers, personal data assistants (PDAs), mobile phones, and the like, due to inherent advantages thereof, such as small size, high capacitance, ease of mounting, and the like.
Generally, in order to develop high capacitance multilayer ceramic capacitors, the dielectric layers included therein should be thinned. Therefore, there has been demand for a dielectric composition allowing for a high permittivity to be implemented without decreasing reliability in spite of the thinness of the dielectric layers, and having a small capacitance decrease rate depending on a direct current (DC) voltage applied thereto.
In accordance with the trend for high capacitance and thinness of multilayer ceramic capacitors, as described above, there is great demand to design a dielectric composition for a capacitor having high permittivity. To date, generally, in a technology for securing high permittivity, the object of achieving high permittivity has been achieved by simply causing particle growth to adjust the number of dipoles in crystals.
At the time of designing a high permittivity composition by particle growth as described above, however, a rate of change of capacitance, depending on temperature and a level of DC voltage applied thereto may be increased, and the number of particles per layer of the dielectric layers may be decreased, such that reliability may be deteriorated.
In order to solve the above-mentioned problem, a method allowing permittivity to be increased without particle growth has been required.